Heat treatment of alloys



Patented Fem 5, 1

wtrau'r OFFICE HEAT TREATMENT OF ALLOYS Michael G.

Corson, Jackson Heights, N. Y., as-

signor to Electro Metallurgical Company, a corporation of West Virginia No Drawing. Original application October, 20,

' 8 Claims.

This application is a division of my copending application Seri al No. 143,017, filed October 20, 1926, and patented January 10, 1933, Number This invention r elates to a method of heat treating alloys which contain copper as their principal amounts constituent and and beryllium. These alof nickel which contain minor loys may also contain nickel and the amount of nickel may be as high as 40%.

A princip part to such al object of my nvention is to imalloys by a suitable heat treatment hardness and strength far in excess of that possessed by metallic copper, thus forming a material having properties 'which permit of its use for many purposes at the present time as wellwhich, copper is not adapted.

In my Patent 1,658,186, dated February ,I have disclosed that containing regulated minor amounts of one ormore of certain silicides, among -silicide, NizSi,

and strong condition will for which copper is used as for other uses to 7, 1928, copper and copper alloys them nickel assume a remarkably hard if subjectedto certain heat treatment of the kind to which the tenn age hardening is usually applied in the art. I have now discovered that a copper alloy containing, in place or nickel silicide, minor amounts of nickel and beryllium may be worked and heat treated in a more or less similar manner.

For example, an alloy containing 95.7% copper, 4% nickel or cold rolled, or otherwise and .3% beryllium can be hot worked, and after the rolling operation subjected to a softening treatment comprising quenching from above 900 C. In this state the alloy is very soft and duetile, and

shows a It also tensile strength of 48,000

quare inch with 60% elongation in possesses a Brinell hardness (500 kg. load, 10 mm. ball) of 52. The quenched alloy can be hardened by subjecting it to a second heat treatment which comprises heating at a temperature within the range of about 350 C. to 700 C. and holding it fora time,

depending upon the temperature used and the hardness desired. Heating for a period of approximately 48 hours will secure maximum" hardness when a temperature of' 350 C. is used, while at a temperature of 700 C. heating for 2 hours will sufiice. above-mentioned have, when subjected to a hardening heat treatment, attained a Brinellha'rd-r ness of and a tensile strength of 90,000 pounds per square inch with 15%. elongation in two inches.

The alloy,

Alloys of the composition when in a hardened state Serial No. 143,017. plication August 13, 1932,- Serial No.

ness under the influence ment,-i. e., heating at period of 6 hours to 350 C.,-the electrical re- Divided and this approduced either by heat treatment or by cold drops from 900 C. to 700 C. in the course of 10 one and one-half hours, thealloy' acquires a hardness of 86 Brinell and a tensile strength of 72,000 pounds 'per square inch with 25% elon-. gation in two inches.

Copper alloys containing from 0.1% to 2% of beryllium and. as high as 40% nickel are considered to be within the scope of the present invention. However, it is preferred that nickel should be' present in the proportion of about 13 parts nickel to 1 part beryllium by weight.

The electrical resistivity of the alloys coming within the present invention can be lowered by heat treatment. For example, the alloy of 95.7% copper, 4% nickel and .3% beryllium abovedescribed has an electrical resistivity of 9.3 microhms per centimeter cube when quenched. By subjecting the alloy to a prolonged heat treat- 700 C. for 1 hour and then gradually reducing the temperature over a sistivity of the alloy is brought down to 3.4 microhms or about three times that of copper. The unquenched' alloy will show approximately the same electrical resistivity if air or furnace cooled from 900 C.

I claim:

1. The method of improving the properties of copper, which comprises alloying the copper with about 0.1% to 2% beryllium and with about 0.1% to 40% nickel, heating the alloy at temperatures 40 above about 900 C. and below its melting point, whereby the alloy is softened, and subsequently heating the alloy at temperatures between about 350 C. and 900 0., whereby the alloy is hardened.

2. Process of treating an alloy containing 45 copper as its principal ingredient, about 0.1% to 40% nickel, and about 0.1% to about 2% beryllium, which comprises heating the alloy at temperatures above about 900 C. and below its melting point, quenching the alloy, and then heating the alloy at temperatures between about 350 C. and 700 C. v

3. Process of treating an alloy consisting predominately of copper and containing about 0.1% to 40% nickel and about 0.1% to 2% berylliumalloy; toabove Q OO C. and below its melting point, and then allowing the alloy to cool slowly.

4. Process of treating an alloy consisting predominately of copper and containing about 0.1% to 40% nickel and about 0.1% to 2% beryllium which comprises working the alloy, heating the alloy to above 900 C. and below its melting point, and then allowing-the alloy-to cool in air. q

5. Process of treating an alloy containing copper as its principal constituent and about 0.1%

to 40% nickel and about 0.1% to 2% beryllium which comprises working the alloy; heating the worked alloy to a temperature above 900 C. and below its melting point, quenching; and then heating the alloy at a temperature above 350 C. and below about 700 for a sufiicient-time to impartthe desired degree of hardness thereto. 6. Process of treating an alloy containing copper as its principal constituent and about 0.1% to 40% nickel and about 0.1% to 2% beryllium,

1,990,168 which comprises working the alloy, heating the which comprises heating point, quenching the alloy, and then heating the alloy at temperatures between about 350 C. and 700 C. v

7. Process of treating alloys-consisting predominately of copper and containing about 0.1% to 40% nickel and about 0.1% to 2% beryllium, which comprises heating the alloy'to temperatures above about 900 C. and below its melting point, and then allowing the alloy to cool slowly.

8. An article comprising an alloy having copperas its principal constituent and containing nickel and beryllium, the beryllium being not in excess of about 2% and the excess of about 40%, which nickel being not in alloy has been softhe alloy at temperatures above about 900 C. and belowits melting tened by heating at temperatures above about 900 C. and below its' melting point, and subsequently hardened by heating the alloy above about 350 C. and below about 900 C.

MICHAEL G. CORSON. 

